ASSESSING AND EXPLAINING MISPERCEPTIONS OF PEER DELINQUENCY*

Peer delinquency is a robust correlate of delinquent and criminal behavior. However, debate continues to surround the proper measurement of peer delinquency. Recent research suggests that some respondents are likely to misrepresent their peers’ involvement in delinquency when asked in survey questionnaires, drawing into question the traditional (i.e., perceptual) measurement of peer delinquency. Research also has shown that direct measures of peer delinquency (e.g., measures obtained via networking methods such as Add Health), as compared with perceptual measures, differentially correlate with key theoretical variables (e.g., respondent delinquency and respondent self‐control), raising the question of whether misperception of peer delinquency is systematic and can be predicted. Almost no research, however, has focused on this issue. This study, therefore, provides detailed information on respondents’ misperceptions of peer behavior and investigates whether individual characteristics, the amount of time spent with peers, and peer network properties predict these misperceptions. Findings indicated that 1) some individuals—to varying degrees—misperceived the delinquent behavior of their peers; 2) self‐control and self‐reported delinquency predicted misperception; 3) respondents occupying densely populated peer networks were less likely to misperceive their peers’ delinquent involvement; and 4) peers who occupy networks in which individuals spend a lot of time together were more likely to misperceive peer delinquency. Implications are discussed.     

Availability of target odor compounds from seized ecstasy tablets for canine detection

The aim of this study was to compare seized samples of 3,4-methylenedioxy-N-methylamphetamine (MDMA) pills, used to train law enforcement detection canine teams, to determine what differences exist in the chemical makeup and headspace odor and their effect on detectability. MDMA solutions were analyzed by liquid chromatography-mass spectrometry. Analysis of these samples showed a wide variance of MDMA (8-25%). Headspace SPME-GC/MS analysis showed that several compounds such as 3,4-methylenedioxyphenylacetone and 1-(3,4-methylenedioxyphenyl)-2-propanol are common among these MDMA samples regardless of starting compound and synthesis procedure. However, differences, such as the level of the various methylenedioxy starting compounds, were shown to affect the overall outcome of canine detection, indicating the need for more than one MDMA training aid. Combinations of compounds such as the primary odor piperonal in conjunction with a secondary compound such as MDP-2-OH or isosafrole are recommended to maximize detection of different illicit MDMA samples.     

Analysis and discrimination of electrical tapes: part II. Backings

The backings of 90 black electrical tapes were analyzed to evaluate the chemical components of these films, the ability of individual techniques to discriminate samples, and the ability of the techniques combined to distinguish samples. The techniques utilized and their respective discrimination results were stereomicroscopy and physical measurements, to include observation of surface features of the backing, width, and thickness measurements (c. 64%); Fourier transform infrared spectroscopy (FTIR) using a microscope accessory (c. 83%); pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS; c. 81%); and scanning electron microscopy/energy-dispersive spectroscopy (SEM/EDS; c. 87%). Ninety-four percent of the backings were discriminated through this combination of analytical methods. Finally, evaluating these results in conjunction with previously published data on the analysis of the adhesives from the same set of electrical tapes provided an overall discrimination of nearly 96%.     

Comparisons of familial DNA database searching strategies

The current familial searching strategies are generally based on either Identity-By-State (IBS) (i.e., number of shared alleles) or likelihood ratio (i.e., kinship index [KI]) assessments. In this study, the expected IBS match probabilities given relationships and the logic of the likelihood ratio method were addressed. Further, the false-positive and false-negative rates of the strategies were compared analytically or by simulations using Caucasian population data of the 13 CODIS Short Tandem Repeat (STR). IBS ≥ 15, IBS ≥ 16, KI ≥ 1000, or KI ≥ 10,000 were found to be good thresholds for balancing false-positive and false-negative rates. IBS ≥ 17 and/or KI ≥ 1,000,000 can exclude the majority of candidate profiles in the database, either related or not, and may be an initial screening option if a small candidate list is desired. Polices combining both IBS and KI can provide higher accuracy. Typing additional STRs can provide better searching performance, and lineage markers can be extremely useful for reducing false rates.     

Spheno-occipital synchondrosis fusion in modern Americans

This study examines spheno-occipital synchondrosis fusion in the modern American population and presents age ranges for forensic use. The sample includes 162 modern individuals aged 5-25 years. The basilar synchondrosis was scored as open, closing, or closed via direct inspection of the ectocranial site of the suture. Transition analysis was used to determine the average ages at which an individual transitions from unfused to fusing and from fusing to fused. The maximum likelihood estimates from the transition analysis indicate that females are most likely to transition from open to closing at 11.4 years and males at 16.5 years. Females transition from closing to closed at 13.7 years and males at 17.4 years. The probability distributions associated with these maximum likelihood estimates were used to derive age ranges for age estimation purposes. These results reflect sexual dimorphism in basilar synchondrosis fusion and agree approximately with average age at pubertal onset.     

Fatal traffic injuries among children and adolescents in three cities (capital Budapest, Vilnius, and Tallinn)

Motor vehicle accidental injuries are a frequent cause of death among young children and adolescents. The goal of this study was to compare patterns of injury between three capitals (Budapest, Vilnius, and Tallinn). Information on 190 fatal traffic accidents (69 pedestrians, 14 bicyclists, and 107 motor vehicle occupants) between 2002 and 2006 was collected from databases of medico-legal autopsies. The role of victims in accidents, the location of injuries, cause of death, survival period, and blood alcohol levels were evaluated. One-hundred and forty-one (74%) victims had a passive role in traffic as pedestrians, passengers in cars, or public transport. In victims who died at the scene, the rate of head injury was higher than in cases who received medical treatment (odds ratio = 2.58, CI = 1.2-5.55, p = 0.0127). These results underline the importance of postmortem studies to examine the pathomechanism of fatal traffic accidental injuries and to provide information for the prevention of road traffic accidents against children and adolescents.     

Differentiation of unevaporated gasoline samples according to their brands, by SPME-GC-MS and multivariate statistical analysis

One of the aims of fire investigations is to identify associations among accelerants according to their source. In this study, 50 gasoline samples--representing five brands--were analyzed using solid-phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS). Chemometric procedures, such as principal component analysis (PCA) and discriminant analysis (DA), were applied to a data matrix obtained by the target compound chromatogram method, to discriminate samples according to their brand. PCA was successful in finding a natural grouping of samples according to their brand, suggesting that aromatic compounds were more useful than aliphatics for the purpose of this study. DA, if applied to aromatic compounds, gave both a classification ability and a prediction ability of 100%. The outstanding results obtained by this work provide the basis of a data matrix that could be used in real cases of arson to link a sample of unevaporated gasoline to its brand or refinery.     

The prevalence of mental disorders in prisoners in the city of Salvador, Bahia, Brazil

The number of individuals affected by serious psychiatric disorders in Brazilian prisons is unknown. This cross-sectional study was conducted in prison complexes within the city of Salvador, Bahia, Brazil. The sample consisted of 497 prisoners, and the outcome measure was the Brazilian Portuguese version of the Mini International Neuropsychiatric Interview. The prevalence rates found in the closed and semi-open prison systems, respectively, were as follows: depression 17.6% and 18.8%; bipolar mood disorder 5.2% and 10.1%; anxiety disorders 6.9% and 14.4%; borderline personality disorder 19.7% and 34.8%; antisocial personality disorder 26.9% and 24.2%; alcohol addiction 26.6% and 35.3%; drug addiction 27.9% and 32.4%; psychosis 1.4% and 12.6%; attention deficit/hyperactivity disorder (ADHD) in childhood 10.3% and 22.2%; and ADHD in adulthood 4.1% and 5.3%. This study revealed higher rates of substance-related disorders and lower rates of psychotic and mood disorders compared to other prevalence studies carried out in prison populations.     

Expression and function of C5a receptor in a fatal anaphylaxis after honey bee sting

The mechanisms leading to death from anaphylaxis after insect sting involve antigen cross-linkage of antibody molecules that activate immunoglobulin receptors on inflammatory cells. The aim of our study was to investigate the pathomorphology and the expression of C5aR in fatal anaphylaxis in a patient after a fatal insect sting. A 38-year-old women was stung by a honeybee. C5R1 expression was detected in many dilated capillaries in the lungs. Pulmonary epithelial cells did not bind the monoclonal antibody for C5R1; however, intensive cytoplasmic staining was detected in endothelial cells. The findings of this case provide evidence for an active role of complement in fatal anaphylaxis elicited by bee venom. C5aR detection could be useful in the identification of sudden death cases because of unwitnessed fatal insect sting cases. Authors can recommend this immunohistochemical analysis on all sudden unexpected deaths outdoors where a possible bee sting might occur.     

The evaluation of human hand odor volatiles on various textiles: a comparison between contact and noncontact sampling methods

The focus of this study is to compare contact and noncontact human scent collection procedures across an array of textiles (cotton, rayon, polyester, and wool) to determine an optimized collection method for human scent evidence. Six subjects were sampled in triplicate for each textile and collection mode, and the samples were then analyzed through headspace solid-phase micro-extraction in combination with gas chromatography/mass spectrometry (SPME-GC/MS). Contact sampling with cotton material has been shown to be the collection method that yielded the greatest number of volatile compounds and the highest scent mass amounts. Through Spearman rank correlations, it was shown that an individual's scent profile is more reproducible within samples collected on the same textile type than between different materials. Furthermore, contact sampling with cotton fabric demonstrated the greatest reproducibility producing the lowest amount of type I and type II errors with 90.85% of the samples distinguished at the 0.9 match/no match threshold.